Giving children a type of "good bacteria" during their first 6 months of life doesn't reduce their risk of developing allergies in early childhood, researchers from Australia report.
But it's possible that other strains of probiotics could be more helpful in allergy prevention, Dr. Susan L. Prescott and colleagues from the University of Western Australia in Perth note in the journal Allergy.
Based on the "hygiene hypothesis" -- or the idea that children in the developed world are increasingly likely to develop asthma and other allergic conditions because they are living in overly clean environments -- probiotics are being investigated both for treating these conditions and possibly preventing them.
In a previous study, Prescott and colleagues gave 178 children either a preparation of the good bacteria Lactobacillus acidophilus every day for their first 6 months of life or a placebo. At 1 year of age, they found the children given the good bacteria were actually more likely to develop sensitivity to allergens.
However, when the children were 2-and-a-half years old, there was no difference between the probiotic group and the placebo group in the likelihood of developing rashes or other allergic conditions, and the children who had taken the probiotic were no longer more likely to develop allergen sensitivity.
While these children did have significantly fewer gastrointestinal infections in the previous 18 months than those given placebo, the findings should be interpreted cautiously given that the study wasn't designed to look at this effect, the researchers say.
"While the probiotic selected in this study did not appear to have a role in allergy prevention, other strains have shown more promise and these differences are likely to reflect multiple strain, host and environmental differences in these populations," Prescott and colleagues conclude.